Processing kodak motion picture films, module 3 analytical procedures

APPARATUS
All volumetric glassware should meet all “Class A”
specifications, as defined by the American Society for
Testing and Materials (ASTM) Standards E 287, E 288, and
E 969 unless otherwise stated.
Manual Titration
pH Meter, ORION EA 940, or equivalent
pH Indicator electrode, CORNING Model 476024, or
equivalent
Calomel reference electrode filled with 3.5 N KCl,
CORNING Model 476002, or equivalent
50-mL Buret
Automatic Titration
Titrator, METROHM 682, or equivalent
pH Indicator electrode, CORNING Model 476024, or
equivalent
Calomel reference electrode filled with 3.5 N KCl,
CORNING Model 476002, or equivalent
REAGENTS
All reagents used are ACS Reagent Grade unless otherwise
stated.
Water, Type I Reagent – This method was developed
using reagent water equivalent to purer than Type I Grade,
as defined in ASTM Standard D 1193. Other grades of
water, e.g., reverse osmosis (RO), demineralized, or
distilled water, may give equivalent results, but the effects
of water quality on method performance have not been
studied.
0.1 N Sulfuric Acid, standardized to four decimal places.
If an autotitration system is being used, then the sulfuric
acid should be standardized by using an automated
system.
PROCEDURE
Manual Titration
Titration of the Sample
1. Using Method ULM-191-2, pH Measurement of
Photographic Processing Solutions (or any
subsequent pH method), calibrate the pH meter for
making pH measurements below pH 7.
2. Pipet (wipe the pipet before leveling) 5.0 mL of
sample into a 150-mL beaker containing 50 mL of
reagent water and a Teflon-coated stir bar.
3. Rinse the electrodes with reagent water and blot the
electrodes with a tissue.
4. Place the electrode assembly and the tip of the buret (if
possible) into the solution. Turn on the stirrer.
5. Using a 50-mL buret, titrate the sample solution with
0.1000 N sulfuric acid to a pH of 4.3.
a. Add 1 mL increments of sulfuric acid to the
sample solution until the pH of the solution is 5.
b. Add 0.1 mL of sulfuric acid to the sample
solution. When the pH of the solution reaches
4.5, record the volume of acid corresponding to
the pH value. Continue to titrate until the pH of
solution is less than 4.3 and record the pH after
each 0.1 mL addition.
c. For the calculation of total alkalinity, use the
volume of acid that resulted in the solution pH
that was closest to 4.300. For example, if
29.9 mL of acid resulted in a pH of 4.309, and
30.0 mL of acid resulted in a pH of 4.297, use
30.0 mL of acid in the calculation.
Calculations
1. To calculate the total alkalinity (TA), use the
following formula:
Where:
TA = (N acid )(mL acid )/0.1
Nacid = actual normality of sulfuric acid used
mLacid = millilitres of sulfuric acid used
0.1 = corrects the actual normality of sulfuric acid
to 0.1000 N sulfuric acid
2. The total alkalinity is reported to a tenth of a millilitre
(0.1 mL).
Note: The sample size used to determine the total
alkalinity of a solution must be included when
reporting results. For example, the total alkalinity of
solution X is 24.5 mL for a 5.0 mL sample size.
2 Processing KODAK Motion Picture Films, Module 3, Analytical Procedures H24.03